1. Field of the Invention
The present invention relates to a mobile communication handset, and more particularly to a speaker installed in a handset for mobile communication.
2. Background of the Related Art
Generally, a speaker used for various electronic products converts an inaudible electrical voice signal to an audible signal. Small sized electronic products such as electronic pocket books, organizers and handsets for mobile communications (e.g., cellular phones and personal communication service (PCS) phones) require a relatively small sized overall product and a relatively large sized display, such as a liquid crystal display (LCD), to show various information to a user. To achieve this sizing, various suggestions, such as miniaturization of various components used for electronic products and variations in arrangement of the components, have been advanced.
The speaker, however, has properties such that the distance between the speaker and the ears of the user, as well as extremely fine vibrations and space structure of the speaker can vary the sound quality. For such reasons, it was difficult to reduce the size of the speaker used for small sized electronic products beyond a certain limit. It was also detrimental to change the installation position and/or structure of the speaker.
Accordingly, a related art speaker is formed in a case of the electronic product parallel and close to a sound propagation hole, which propagates an audible signal generated by the speaker to the outside. An example of the related art speaker for a handset for mobile communication will be described with reference to FIGS. 1 and 2.
Referring to FIG. 1, an LCD 20 for displaying characters is provided in a main body, i.e., a case 2 of a handset 1. A sound propagation hole 15 is formed in an upper side of the case 2, above the LCD 20, to propagate the sound generated by a speaker 10, which is provided inside the case 2. A microphone 12 and a flip 3 are provided in a lower side of the case 2.
Referring to FIG. 2, at the rear of the sound propagation hole 15 formed in a front side 2a of the case 2, the speaker 10 is provided parallel to the front side 2a of the case 2. A filter 50 is provided between the sound propagation hole 15 and the speaker 10 so as to prevent any foreign substance, such as dust, from getting into the speaker 10. The filter 50 is attached to an inner side of the case 2 by a first piece of double-sided adhesive tape 40, and attached to the speaker 10 by a second piece of double-sided adhesive tape 45.
The operation of the related art speaker for the handset will now be described. If an electrical signal reaches the handset 1, the electrical voice signal is converted to an audible signal by the speaker 10. The audible signal remains in the case 2 for a while due to resistance and then is propagated to an ear of the user through the filter 50 and the sound propagation hole 15. The filter 50 prevents any foreign substance from adhering to the speaker, and prevents deterioration of the speaker's 10 performance.
The related art handset has various problems. Recent trends in handset design have sought to reduce the handset's overall length in order to facilitate carrying and custody. By contrast, it is desirable that the size of the LCD become larger as data communication using a mobile communication system has increased. However, the extent to which the related art handset for a mobile communication can meet such requirements is limited. That is, since the related art speaker 10 is attached parallel to the front side 2a of the handset 1, the portion of the handset where the speaker 10 is mounted necessarily occupies a length greater than a diameter D of the speaker. This limits the extent to which the handset length can be reduced. Furthermore, since the speaker 10 occupies a relatively large space in the handset having a limited size, the amount of space available to the LCD 20 is reduced.
Such problems cannot be solved by simply varying the installation position and structure of the speaker. As aforementioned, since the speaker has properties that vary the sound depending on the distance between the speaker and the user's ear, as well as on the extremely fine vibration and space structure of the speaker, the volume or articulation of the sound may be deteriorated if any variation is made to only the installation position or structure of the speaker.
The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background.